Today is National Arbor Day. This special day encourages the care and planting of trees. A man by the name of J. Sterling Morton began the effort that led to Arbor Day in the 1850’s. Over the years his work and dedication led to the first national observance of Arbor Day in 1872. It is now celebrated nationally on the last Friday in April.

To learn more about the enthusiasm and community support of Mr. Morton’s ideas click here.

Suggestions on how to celebrate Arbor Day can be found here. It is important to note that state celebrations can differ from the national date. State Arbor Day celebrations are often observed to coincide with appropriate local planting times for trees.

California’s oak trees are facing another challenge to their survival. The gold-spotted oak borer (GSOB) was identified in California in 2006; since that time, over 17,000 oaks have died from this pest.

The loss of oak trees, especially in the wild, brings many negative impacts: loss of wildlife habitat, greater risk of erosion and catastrophic fire, invasion of noxious weeds, as well as safety risks related to falling trees or branches.

The borer attacks the trunks and branches of mature oaks. While most pests attack trees that are stressed or weakened, the GSOB attacks large, healthy trees – including trees in yards. Thus far the damage has been contained to San Diego County.

Much work is being conducted in an effort to learn more about the GSOB. With more knowledge, researchers hope to be able to stop the destruction of these magnificent trees. At this time, all we can do is work together to slow the spread of the GSOB with the following steps:

Do not transport oak firewood into or out of campgrounds or parks

Chip infested oak wood to 1-inch pieces

Cover stored oak firewood with 6 mm, UV-stabilized, durable plastic tarps in the spring. Secure all the edges of the tarp to the ground to prevent beetles from escaping

Season oak firewood. Remove the bark and place the wood in direct sunlight

Pictures of the borer, the damage caused, and more information can be found here.

Have you been considering adding a tree to your landscape? If so, fall is a good time to plant trees. A recent post on UC’s The California Practical Gardener blog explains why now is a good time for tree planting. Links to information to help readers find a good tree for their location is also provided.

Ventura County UCCE Environmental Horticultural Advisor, Jim Downer has great tips on what to look for at the nursery and placing the tree in your landscape to achieve the best possible chance for the long-term health of the tree. These tips can be found in Jim’s July 2009 Landscape Notes Newsletter.

Topics include:

Checking nursery container for circling roots

Planting trees at the appropriate depth

How best to anchor, protect or support the tree after planting

Pruning considerations

Water needs

Nutrient needs

Long-term growth considerations

Additional assistance with residential tree questions can be directed to our Master Gardener Helpline at 805.645.1455 or at mgventura@ucdavis.edu. Master Gardeners are at the helpline desk Tuesdays and Thursdays between 1:00 and 4:00. Commercial operation tree questions can be directed to Dr. Downer.